Insulator-thimble.



R. A. BECKER L T. E. MADDEX.

INSULATOR THIIYIBLE.

APPLICATION FILED JUNE 6.19I1.

l ,268,3 l 5 l Patented June 4, 1918.

I IIl RAYMOND A'. BECKERAND'THOMAS E. MADDEX,'F"HILLSBORO, ILLINOIS.

INSULATOR-THIMBLE.

l Specification of Letters Patent.

Patented J une 4, 1918.

Application ined June 6, 19-17. serial' No. 173,162.

To all whom z5 may concern:

Be it known that we, RAYMOND A. BECKER and THOMAS E. MADDEX, citizens ofthe UnitedStates, and residents of Hillsboro, iny the lcounty ofMontgomery and State of Illinois, have inventedcertain new and usefulImprovements' in Insulator-Thimbles, of which the following is aspecification.

The present invention relates to insula-y tors, andmore particularly tothat type of insulatoradaptedl to be supportedv uponA pins orstud'susually carried upon cross-arms and the like, for supporting' andinsulating line wires of high and low tension. d

In priorV insulator construction, wooden pins have been employed whicharescrewed directly into the insulator body. Thechief objectionV foundto such a construction has been that in the larger size insulators',such asl are used in high-tension transmission,

wood pins are unsuitable on account: of mechanical'weak-ness. This hasbeen attempted tobe overcome by'theprovision of 'metallic pins ofsufficient strength but they are found unsatisfactory' on account ofthe' tendency to cramp the threads and thus'l injure lthe body of theinsulator. Ithas also beenk attempted to overcome the defect by theprovision of a metal pin which is cemented directly into the insulatorpin hole. This, however, has the disadvantagey thatA in installing, thelcombined weightof the assem bled pin and insulator body is too heavytoV'be' conveniently handled in Xing the pin or stud tothe cross-arm orother support employed. Further, objection is also found in this lattertype of insulator mounting for thel reason that the cement, which is'practically unyielding, transmits or communicates to the rwalls oftheinsulator body all of the mechanical stressesset up by the eXpansionand contraction of the metal pin.

Various other attempts have beenmade to overcome all of,V theseobjections, and a further attempt has been embodied in providing a metalthimble which is internally threaded for detachable'engageinent with ametallicpin or stud, the thimble being cemented into the openingr in theinsulator body. Itis readily seen vthat' while thisv latter constructionadmits of the separate mounting of the pin upon ,theV cross-arm' orother support, does not offset the transmission"'or communication of1mechanical stresses set up by the expansion and contractionof the metalpin and the thimble to the adjacent walls of the insulator body, thuscracking and breaking the latter. There is one 'instance familiar to thepresent inventors which embodies the threading of the pin, the threading4of a shell over the pin which is made of relatively thin metal, andwhich has the threads thereof pressed into thebody of the shell, andwhich is cemented inl the insulator body. The closed end of the fshellis provided with a cork inn sertfadapted to cushion .and take upeXpansion' and contraction of the pin, longitudinally. However, thetransverse or diametrical expansion and contraction of the pin is notprovided for, and such resultant stresses of the thimble causes thecracking and breaking of ythelinsulator body. e

It is the object of the present invention to overcome all ofthesedefects by providing a novel form of thimble capable of taking upnot only the longitudinal mechanical stresses incident to the lexpansionIand contraction of the pin andthe thimble, but also the lat-eral or'transverse mechanical stresses, and to provide athimble which may beeasily re-V moved and rreplaced upon the stud end of the pin, and'whichmay be cemented securely in the insulator body.

The above, yand'various other objects and advantages of'this inventionwill be in part described, and in part understood, from the followingdetailed, description of the present preferred embodiment, the samebeing illustrated in the accompanying drawing, wherein:

Figure l is a longitudinal section through an. insulator provided with athimble constructed according to the present invention, the thimblebeing shown in elevation.

Fig. 2 is a longitudinal view, enlarged.l of th'ethimble.l disclosedpartly in section, and partly in elevation.

Fig. 3 'is a transverse section taken substantially on the line 3-3 ofFig. 2, through the insulator thimble, showing the spacing between theinner and outer sections thereof.

' Referringto this drawing, 10 designates the body of an insulator whichmay be formed of a plurality of sections in the usual manner securedtogether in interfitting relation by films of cement 11, or the like.

In the 'present embodiment, the thimble comprises an inner tubularsection 12 of metal, or the like, provided with internal screw-threadsadapted to receive a supporting pin therein, and admitting of theremoval and positioning of the thimble upon the pin by merely screwinorand unscrewing' the thimble with respect tliereto. The base or lower endof the inner section 12 of the thimble is provided with an annular out--standing flange lhaving a relatively flat lower end or base portionadapted to bind against the pin-and thus securely hold the thimble fromturning upon the pin when the thimble is secured in position. Theopposite end of the thimble section l2 is provided with a closure wall14 vwhich may engage the upper end of the supporting pin or arm.

The thimble is provided with an outer or shell section 15 preferablyformed from sheet metal and tubular in shape. The outer section 15 isadapted to fit loosely over the inner section 12 and preferably forms anannular space between the two sections, as shown in Fig. 3. This annularspace provides for the transverse expansion and contraction of the innerthimble section 12, and the outer shell section 15 is preferably ofslightly greater length than the inner section 12 to provide a spacevbetween the closure wall 14 of the inner section and the upper closedsection 16 ofV the outer section. y

The outer shell section 15 is preferably corrugated annularly to provideperipheral beads and depressions or grooves arranged alternately fromend to end of the shell section 15 for the purpose of absorbinglongitudinal and transverse mechanical stresses incident to expansionand contraction of the parts. and also to aord anchoring means adaptedto be embedded in the cement 17,

or other securing body, adapted to hold the thimble in the opening ofthe insulator body 10. Y

The open or base end of the shell section 15 is formed into a iiaringflange 18 which is spun or otherwise suitably formedabout the marginaledgev of the base flange 13 of the inner section 12. for the purpose offirmly uniting the sections 12 and 15 of the thimble. It will be notedthat the marginal edge of the flange 18 of the outer section 15 .isturned inwardly beneath the base portion of the iiange 13 so as tofirmly hold the shell section 15 from longitudinal .displacement fromthe inner section 12.

It will be noted that the thimble of this invention comprises inner andouter sections which are spaced apart annularly and longitudinally sothat the sections are arranged substantially concentric with respect toeach other and the said sections are permitted to expand and contractindependently of each other without communithe outer shellv 15 may beformed from sheet` metal, or the like, such as drawn steel, and that theparts are firmly united by spinning or overturning the free end iiangeof the outer shell about the base flange of the inner section.

K It is of course understood that various changes and modications may bemade in the details of construction and design of the above specificallydescribed embodiment of this invention, without departing from thespirit thereof, and being restricted only by the scope of the followingclaims.

We claim:

1. In an insulator thimble, the combination of an inner cylindricalsection having internal threads and an outstanding base ange, and anouter shell section of greater internal diameter than the externaldiameter of the inner section and provided with a base flange engagingabout the base flange of the inner section to hold the sections inconcentric spaced-apart relation, said outer section being provided withannular corrugations and being of greater length than the inner section.

2. In an insulator thimble, the combination of an inner section ofcylindrical form closed at one end and provided with a base ange at itsopposite end, said inner section having internal threads adapted todetachably engage a supporting pin, and an outer section of tubular formtting over the inner section and provided with a closedA end and anoutwardly flaring flange vat its opposite end adapted to be turned overthe base flange of the inner section for uniting said inner and outersections, the outer section being also provided with annularcorrugations extending from end to end of the outer section to provideperipheral beads adapted to be secured in the opening of an insulatorbody, and adapted to absorb mechanical stresses transmitted to thethimble.

grooves extending from end to end of the Inodate the longitudinalexpansion and conouter section, and adapted to absorb Inetraction of thesections, and Said sections chanical stresses incident to thecontraction being provided at their opposite ends with 10 and expansionof the inner section and supinterlocking base flanges adapted to unite 5porting pin, Said sections being closed at one the same.

end and the outer section being of greater RAYMOND A. BECKER. lengththan the inner section to accom- THOMAS E. MADDEX.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

f Washington, I). C.

